"It made no eccentric moves, and from partway through it felt like I was playing against a human. I'm a bit frustrated by the loss, but I gained respect for the people who took part in developing the software," Shimizu said. "I hope humans and computers will become stronger in the future through friendly competition."

"Akara," after which the shogi system was named, is a Buddhist term meaning "10 to the power of 224," a figure close to the total possible number of unique shogi games. The system combines four shogi software programs -- Gekisashi, GPS Shogi, YSS and Bonanza -- and selects the best move through a majority.

In the game with Shimizu, each side had three hours. Akara 2010 played with a "ranging rook" strategy, offering an exchange of bishops. Shimizu made a questionable move partway though the game, and Akara went on to win.

The game was staged after the Information Processing Society of Japan approached the Japan Shogi Association and suggested holding the match.

Society member Hitoshi Matsubara, a professor at Future University Hakodate, said the computer's win came after decades of work.

"I started developing shogi software 35 years ago, and for the software to become this strong is enough for me to forget all the hard work."

In 2005, the Japan Shogi Association introduced a ban on professional members playing shogi computers without permission. The latest game was the first human versus computer game approved by the association since Ryuo champion Akira Watanabe defeated Bonanza in 2007.